[svn-r16182] Description:

	Rename internal routines, variables, macros, typedefs, etc. for chunked
dataset storage from "istore" to some variant of "chunk" or "btree".

Tested on:
        Mac OS X/32 10.5.5 (amazon) in debug mode
        Mac OS X/32 10.5.5 (amazon) w/C++ & FORTRAN, w/threadsafe,
                                in production mode
        FreeBSD/32 6.3 (duty) in debug mode
        FreeBSD/64 6.3 (liberty) w/C++ & FORTRAN, in debug mode
        Linux/32 2.6 (jam) w/PGI compilers, w/C++ & FORTRAN, w/threadsafe,
                                in debug mode
        Linux/64-amd64 2.6 (smirom) w/Intel compilers w/default API=1.6.x,
                                w/C++ & FORTRAN, in production mode
        Solaris/32 2.10 (linew) w/deprecated symbols disabled, w/C++ & FORTRAN,
                                w/szip filter, in production mode
        Linux/64-ia64 2.6 (cobalt) w/Intel compilers, w/C++ & FORTRAN,
                                in production mode
        Linux/64-ia64 2.4 (tg-login3) w/parallel, w/FORTRAN, in production mode
        Linux/64-amd64 2.6 (abe) w/parallel, w/FORTRAN, in production mode

14 files changed, 394 insertions, 399 deletions

diff --git a/src/H5B.c b/src/H5B.c
index a32e830..618cda8 100644
--- a/src/H5B.c
+++ b/src/H5B.c
@@ -2113,7 +2113,7 @@ H5B_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream, int indent, int f
     HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
 	      "Tree type ID:",
 	      ((shared->type->id)==H5B_SNODE_ID ? "H5B_SNODE_ID" :
-            ((shared->type->id)==H5B_ISTORE_ID ? "H5B_ISTORE_ID" : "Unknown!")));
+            ((shared->type->id)==H5B_CHUNK_ID ? "H5B_CHUNK_ID" : "Unknown!")));
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
 	      "Size of node:",
 	      shared->sizeof_rnode);
diff --git a/src/H5Bprivate.h b/src/H5Bprivate.h
index c11d02c..93c2d80 100644
--- a/src/H5Bprivate.h
+++ b/src/H5Bprivate.h
@@ -57,6 +57,16 @@
 /* Library Private Typedefs */
 /****************************/
 
+/* B-tree IDs for various internal things. */
+/* Note - if more of these are added, any 'K' values (for internal or leaf
+ * nodes) they use will need to be stored in the file somewhere. -QAK
+ */
+typedef enum H5B_subid_t {
+    H5B_SNODE_ID	 = 0,	/*B-tree is for symbol table nodes	     */
+    H5B_CHUNK_ID	 = 1,	/*B-tree is for chunked dataset storage	     */
+    H5B_NUM_BTREE_ID            /* Number of B-tree key IDs (must be last)   */
+} H5B_subid_t;
+
 /* Define return values from B-tree insertion callbacks */
 typedef enum H5B_ins_t {
     H5B_INS_ERROR	 = -1,	/*error return value			     */
diff --git a/src/H5Bpublic.h b/src/H5Bpublic.h
index df3861f..0016996 100644
--- a/src/H5Bpublic.h
+++ b/src/H5Bpublic.h
@@ -31,17 +31,6 @@
 /* Public headers needed by this file */
 #include "H5public.h"
 
-/* B-tree IDs for various internal things. */
-/* Not really a "public" symbol, but that should be OK -QAK */
-/* Note - if more of these are added, any 'K' values (for internal or leaf
- * nodes) they use will need to be stored in the file somewhere. -QAK
- */
-typedef enum H5B_subid_t {
-    H5B_SNODE_ID	 = 0,	/*B-tree is for symbol table nodes	     */
-    H5B_ISTORE_ID	 = 1,	/*B-tree is for indexed object storage	     */
-    H5B_NUM_BTREE_ID            /* Number of B-tree key IDs (must be last)   */
-} H5B_subid_t;
-
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/H5Dbtree.c b/src/H5Dbtree.c
index 5d24d63..baa4c6b 100644
--- a/src/H5Dbtree.c
+++ b/src/H5Dbtree.c
@@ -16,7 +16,7 @@
 /* Programmer: 	Robb Matzke <matzke@llnl.gov>
  *	       	Wednesday, October  8, 1997
  *
- * Purpose:	Indexed (chunked) I/O functions.  The logical
+ * Purpose:	v1 B-tree indexed (chunked) I/O functions.  The logical
  *		multi-dimensional data space is regularly partitioned into
  *		same-sized "chunks", the first of which is aligned with the
  *		logical origin.  The chunks are given a multi-dimensional
@@ -76,7 +76,7 @@
  * Given a B-tree node return the dimensionality of the chunks pointed to by
  * that node.
  */
-#define H5D_ISTORE_NDIMS(X)	(((X)->sizeof_rkey-8)/8)
+#define H5D_BTREE_NDIMS(X)	(((X)->sizeof_rkey-8)/8)
 
 /******************/
 /* Local Typedefs */
@@ -96,11 +96,11 @@
  *
  * The chunk's file address is part of the B-tree and not part of the key.
  */
-typedef struct H5D_istore_key_t {
+typedef struct H5D_btree_key_t {
     uint32_t	nbytes;				/*size of stored data	*/
     hsize_t	offset[H5O_LAYOUT_NDIMS];	/*logical offset to start*/
     unsigned	filter_mask;			/*excluded filters	*/
-} H5D_istore_key_t;
+} H5D_btree_key_t;
 
 /*
  * Data exchange structure for indexed storage nodes.  This structure is
@@ -110,72 +110,68 @@ typedef struct H5D_istore_key_t {
  *
  * (Just an alias for the "common" info).
  */
-typedef H5D_chunk_common_ud_t H5D_istore_ud0_t;
+typedef H5D_chunk_common_ud_t H5D_btree_ud0_t;
 
 /* B-tree callback info for iteration over chunks */
-typedef struct H5D_istore_it_ud_t {
+typedef struct H5D_btree_it_ud_t {
     H5D_chunk_common_ud_t common;		/* Common info for B-tree user data (must be first) */
     H5D_chunk_cb_func_t cb;                     /* Chunk callback routine */
     void		*udata;	                /* User data for chunk callback routine */
-} H5D_istore_it_ud_t;
+} H5D_btree_it_ud_t;
 
 
 /********************/
 /* Local Prototypes */
 /********************/
 
-static herr_t H5D_istore_shared_create(const H5F_t *f, H5O_layout_t *layout);
+static herr_t H5D_btree_shared_create(const H5F_t *f, H5O_layout_t *layout);
 
 /* B-tree iterator callbacks */
-static int H5D_istore_idx_iterate_cb(H5F_t *f, hid_t dxpl_id, const void *left_key,
+static int H5D_btree_idx_iterate_cb(H5F_t *f, hid_t dxpl_id, const void *left_key,
     haddr_t addr, const void *right_key, void *_udata);
 
 /* B-tree callbacks */
-static H5RC_t *H5D_istore_get_shared(const H5F_t *f, const void *_udata);
-static herr_t H5D_istore_new_node(H5F_t *f, hid_t dxpl_id, H5B_ins_t, void *_lt_key,
-				  void *_udata, void *_rt_key,
-				  haddr_t *addr_p /*out*/);
-static int H5D_istore_cmp2(H5F_t *f, hid_t dxpl_id, void *_lt_key, void *_udata,
-			    void *_rt_key);
-static int H5D_istore_cmp3(H5F_t *f, hid_t dxpl_id, void *_lt_key, void *_udata,
-			    void *_rt_key);
-static htri_t H5D_istore_found(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_lt_key,
-			       void *_udata);
-static H5B_ins_t H5D_istore_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
-				   hbool_t *lt_key_changed, void *_md_key,
-				   void *_udata, void *_rt_key,
-				   hbool_t *rt_key_changed,
-				   haddr_t *new_node/*out*/);
-static H5B_ins_t H5D_istore_remove( H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
-                  hbool_t *lt_key_changed, void *_udata, void *_rt_key,
-                  hbool_t *rt_key_changed);
-static herr_t H5D_istore_decode_key(const H5F_t *f, const H5B_t *bt, const uint8_t *raw,
-				    void *_key);
-static herr_t H5D_istore_encode_key(const H5F_t *f, const H5B_t *bt, uint8_t *raw,
-				    void *_key);
-static herr_t H5D_istore_debug_key(FILE *stream, H5F_t *f, hid_t dxpl_id,
-                                int indent, int fwidth, const void *key,
-                                    const void *udata);
+static H5RC_t *H5D_btree_get_shared(const H5F_t *f, const void *_udata);
+static herr_t H5D_btree_new_node(H5F_t *f, hid_t dxpl_id, H5B_ins_t, void *_lt_key,
+    void *_udata, void *_rt_key, haddr_t *addr_p /*out*/);
+static int H5D_btree_cmp2(H5F_t *f, hid_t dxpl_id, void *_lt_key, void *_udata,
+    void *_rt_key);
+static int H5D_btree_cmp3(H5F_t *f, hid_t dxpl_id, void *_lt_key, void *_udata,
+    void *_rt_key);
+static htri_t H5D_btree_found(H5F_t *f, hid_t dxpl_id, haddr_t addr,
+    const void *_lt_key, void *_udata);
+static H5B_ins_t H5D_btree_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr,
+    void *_lt_key, hbool_t *lt_key_changed, void *_md_key, void *_udata,
+    void *_rt_key, hbool_t *rt_key_changed, haddr_t *new_node/*out*/);
+static H5B_ins_t H5D_btree_remove( H5F_t *f, hid_t dxpl_id, haddr_t addr,
+    void *_lt_key, hbool_t *lt_key_changed, void *_udata, void *_rt_key,
+    hbool_t *rt_key_changed);
+static herr_t H5D_btree_decode_key(const H5F_t *f, const H5B_t *bt,
+    const uint8_t *raw, void *_key);
+static herr_t H5D_btree_encode_key(const H5F_t *f, const H5B_t *bt,
+    uint8_t *raw, void *_key);
+static herr_t H5D_btree_debug_key(FILE *stream, H5F_t *f, hid_t dxpl_id,
+    int indent, int fwidth, const void *key, const void *udata);
 
 /* Chunked layout indexing callbacks */
-static herr_t H5D_istore_idx_init(const H5D_chk_idx_info_t *idx_info);
-static herr_t H5D_istore_idx_create(const H5D_chk_idx_info_t *idx_info);
-static herr_t H5D_istore_idx_insert(const H5D_chk_idx_info_t *idx_info,
+static herr_t H5D_btree_idx_init(const H5D_chk_idx_info_t *idx_info);
+static herr_t H5D_btree_idx_create(const H5D_chk_idx_info_t *idx_info);
+static herr_t H5D_btree_idx_insert(const H5D_chk_idx_info_t *idx_info,
     H5D_chunk_ud_t *udata);
-static herr_t H5D_istore_idx_get_addr(const H5D_chk_idx_info_t *idx_info,
+static herr_t H5D_btree_idx_get_addr(const H5D_chk_idx_info_t *idx_info,
     H5D_chunk_ud_t *udata);
-static int H5D_istore_idx_iterate(const H5D_chk_idx_info_t *idx_info,
+static int H5D_btree_idx_iterate(const H5D_chk_idx_info_t *idx_info,
     H5D_chunk_cb_func_t chunk_cb, void *chunk_udata);
-static herr_t H5D_istore_idx_remove(const H5D_chk_idx_info_t *idx_info,
+static herr_t H5D_btree_idx_remove(const H5D_chk_idx_info_t *idx_info,
     H5D_chunk_common_ud_t *udata);
-static herr_t H5D_istore_idx_delete(const H5D_chk_idx_info_t *idx_info);
-static herr_t H5D_istore_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
+static herr_t H5D_btree_idx_delete(const H5D_chk_idx_info_t *idx_info);
+static herr_t H5D_btree_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
     const H5D_chk_idx_info_t *idx_info_dst);
-static herr_t H5D_istore_idx_copy_shutdown(H5O_layout_t *layout_src,
+static herr_t H5D_btree_idx_copy_shutdown(H5O_layout_t *layout_src,
     H5O_layout_t *layout_dst);
-static herr_t H5D_istore_idx_size(const H5D_chk_idx_info_t *idx_info,
+static herr_t H5D_btree_idx_size(const H5D_chk_idx_info_t *idx_info,
     hsize_t *size);
-static herr_t H5D_istore_idx_dest(const H5D_chk_idx_info_t *idx_info);
+static herr_t H5D_btree_idx_dest(const H5D_chk_idx_info_t *idx_info);
 
 
 /*********************/
@@ -183,18 +179,18 @@ static herr_t H5D_istore_idx_dest(const H5D_chk_idx_info_t *idx_info);
 /*********************/
 
 /* v1 B-tree indexed chunk I/O ops */
-const H5D_chunk_ops_t H5D_COPS_ISTORE[1] = {{
-    H5D_istore_idx_init,
-    H5D_istore_idx_create,
-    H5D_istore_idx_insert,
-    H5D_istore_idx_get_addr,
-    H5D_istore_idx_iterate,
-    H5D_istore_idx_remove,
-    H5D_istore_idx_delete,
-    H5D_istore_idx_copy_setup,
-    H5D_istore_idx_copy_shutdown,
-    H5D_istore_idx_size,
-    H5D_istore_idx_dest
+const H5D_chunk_ops_t H5D_COPS_BTREE[1] = {{
+    H5D_btree_idx_init,
+    H5D_btree_idx_create,
+    H5D_btree_idx_insert,
+    H5D_btree_idx_get_addr,
+    H5D_btree_idx_iterate,
+    H5D_btree_idx_remove,
+    H5D_btree_idx_delete,
+    H5D_btree_idx_copy_setup,
+    H5D_btree_idx_copy_shutdown,
+    H5D_btree_idx_size,
+    H5D_btree_idx_dest
 }};
 
 
@@ -203,21 +199,21 @@ const H5D_chunk_ops_t H5D_COPS_ISTORE[1] = {{
 /*****************************/
 
 /* inherits B-tree like properties from H5B */
-H5B_class_t H5B_ISTORE[1] = {{
-    H5B_ISTORE_ID,		/*id			*/
-    sizeof(H5D_istore_key_t),	/*sizeof_nkey		*/
-    H5D_istore_get_shared,	/*get_shared		*/
-    H5D_istore_new_node,	/*new			*/
-    H5D_istore_cmp2,		/*cmp2			*/
-    H5D_istore_cmp3,		/*cmp3			*/
-    H5D_istore_found,		/*found			*/
-    H5D_istore_insert,		/*insert		*/
+H5B_class_t H5B_BTREE[1] = {{
+    H5B_CHUNK_ID,		/*id			*/
+    sizeof(H5D_btree_key_t),	/*sizeof_nkey		*/
+    H5D_btree_get_shared,	/*get_shared		*/
+    H5D_btree_new_node,		/*new			*/
+    H5D_btree_cmp2,		/*cmp2			*/
+    H5D_btree_cmp3,		/*cmp3			*/
+    H5D_btree_found,		/*found			*/
+    H5D_btree_insert,		/*insert		*/
     FALSE,			/*follow min branch?	*/
     FALSE,			/*follow max branch?	*/
-    H5D_istore_remove,          /*remove		*/
-    H5D_istore_decode_key,	/*decode		*/
-    H5D_istore_encode_key,	/*encode		*/
-    H5D_istore_debug_key,	/*debug			*/
+    H5D_btree_remove,          /*remove		*/
+    H5D_btree_decode_key,	/*decode		*/
+    H5D_btree_encode_key,	/*encode		*/
+    H5D_btree_debug_key,	/*debug			*/
 }};
 
 
@@ -227,7 +223,7 @@ H5B_class_t H5B_ISTORE[1] = {{
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_get_shared
+ * Function:	H5D_btree_get_shared
  *
  * Purpose:	Returns the shared B-tree info for the specified UDATA.
  *
@@ -242,11 +238,11 @@ H5B_class_t H5B_ISTORE[1] = {{
  */
 /* ARGSUSED */
 static H5RC_t *
-H5D_istore_get_shared(const H5F_t UNUSED *f, const void *_udata)
+H5D_btree_get_shared(const H5F_t UNUSED *f, const void *_udata)
 {
-    const H5D_istore_ud0_t *udata = (const H5D_istore_ud0_t *) _udata;
+    const H5D_btree_ud0_t *udata = (const H5D_btree_ud0_t *) _udata;
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_get_shared)
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_get_shared)
 
     HDassert(udata);
     HDassert(udata->mesg);
@@ -257,131 +253,85 @@ H5D_istore_get_shared(const H5F_t UNUSED *f, const void *_udata)
 
     /* Return the pointer to the ref-count object */
     FUNC_LEAVE_NOAPI(udata->mesg->u.chunk.btree_shared)
-} /* end H5D_istore_get_shared() */
+} /* end H5D_btree_get_shared() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_decode_key
+ * Function:	H5D_btree_new_node
  *
- * Purpose:	Decodes a raw key into a native key for the B-tree
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *		Friday, October 10, 1997
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5D_istore_decode_key(const H5F_t UNUSED *f, const H5B_t *bt, const uint8_t *raw, void *_key)
-{
-    H5D_istore_key_t	*key = (H5D_istore_key_t *) _key;
-    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
-    size_t		ndims;
-    unsigned		u;
-
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_decode_key)
-
-    /* check args */
-    HDassert(f);
-    HDassert(bt);
-    shared = (H5B_shared_t *)H5RC_GET_OBJ(bt->rc_shared);
-    HDassert(shared);
-    HDassert(raw);
-    HDassert(key);
-    ndims = H5D_ISTORE_NDIMS(shared);
-    HDassert(ndims <= H5O_LAYOUT_NDIMS);
-
-    /* decode */
-    UINT32DECODE(raw, key->nbytes);
-    UINT32DECODE(raw, key->filter_mask);
-    for(u = 0; u < ndims; u++)
-	UINT64DECODE(raw, key->offset[u]);
-
-    FUNC_LEAVE_NOAPI(SUCCEED)
-} /* end H5D_istore_decode_key() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_istore_encode_key
+ * Purpose:	Adds a new entry to an i-storage B-tree.  We can assume that
+ *		the domain represented by UDATA doesn't intersect the domain
+ *		already represented by the B-tree.
  *
- * Purpose:	Encode a key from native format to raw format.
+ * Return:	Success:	Non-negative. The address of leaf is returned
+ *				through the ADDR argument.  It is also added
+ *				to the UDATA.
  *
- * Return:	Non-negative on success/Negative on failure
+ * 		Failure:	Negative
  *
  * Programmer:	Robb Matzke
- *		Friday, October 10, 1997
+ *		Tuesday, October 14, 1997
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_encode_key(const H5F_t UNUSED *f, const H5B_t *bt, uint8_t *raw, void *_key)
+H5D_btree_new_node(H5F_t *f, hid_t dxpl_id, H5B_ins_t op,
+		    void *_lt_key, void *_udata, void *_rt_key,
+		    haddr_t *addr_p/*out*/)
 {
-    H5D_istore_key_t	*key = (H5D_istore_key_t *) _key;
-    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
-    size_t		ndims;
+    H5D_btree_key_t	*lt_key = (H5D_btree_key_t *) _lt_key;
+    H5D_btree_key_t	*rt_key = (H5D_btree_key_t *) _rt_key;
+    H5D_chunk_ud_t	*udata = (H5D_chunk_ud_t *) _udata;
     unsigned		u;
+    herr_t      ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_encode_key)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_new_node)
 
     /* check args */
     HDassert(f);
-    HDassert(bt);
-    shared = (H5B_shared_t *)H5RC_GET_OBJ(bt->rc_shared);
-    HDassert(shared);
-    HDassert(raw);
-    HDassert(key);
-    ndims = H5D_ISTORE_NDIMS(shared);
-    HDassert(ndims <= H5O_LAYOUT_NDIMS);
-
-    /* encode */
-    UINT32ENCODE(raw, key->nbytes);
-    UINT32ENCODE(raw, key->filter_mask);
-    for(u = 0; u < ndims; u++)
-	UINT64ENCODE(raw, key->offset[u]);
-
-    FUNC_LEAVE_NOAPI(SUCCEED)
-} /* end H5D_istore_encode_key() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_istore_debug_key
- *
- * Purpose:	Prints a key.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Thursday, April 16, 1998
- *
- *-------------------------------------------------------------------------
- */
-/* ARGSUSED */
-static herr_t
-H5D_istore_debug_key(FILE *stream, H5F_t UNUSED *f, hid_t UNUSED dxpl_id, int indent, int fwidth,
-		      const void *_key, const void *_udata)
-{
-    const H5D_istore_key_t	*key = (const H5D_istore_key_t *)_key;
-    const H5D_istore_ud0_t	*udata = (const H5D_istore_ud0_t *)_udata;
-    unsigned		u;
+    HDassert(lt_key);
+    HDassert(rt_key);
+    HDassert(udata);
+    HDassert(udata->common.mesg->u.chunk.ndims > 0 && udata->common.mesg->u.chunk.ndims < H5O_LAYOUT_NDIMS);
+    HDassert(addr_p);
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_debug_key)
+    /* Allocate new storage */
+    HDassert(udata->nbytes > 0);
+    H5_CHECK_OVERFLOW(udata->nbytes, uint32_t, hsize_t);
+    if(HADDR_UNDEF == (*addr_p = H5MF_alloc(f, H5FD_MEM_DRAW, dxpl_id, (hsize_t)udata->nbytes)))
+        HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "couldn't allocate new file storage")
+    udata->addr = *addr_p;
 
-    HDassert(key);
+    /*
+     * The left key describes the storage of the UDATA chunk being
+     * inserted into the tree.
+     */
+    lt_key->nbytes = udata->nbytes;
+    lt_key->filter_mask = udata->filter_mask;
+    for(u = 0; u < udata->common.mesg->u.chunk.ndims; u++)
+        lt_key->offset[u] = udata->common.offset[u];
 
-    HDfprintf(stream, "%*s%-*s %u bytes\n", indent, "", fwidth, "Chunk size:", (unsigned)key->nbytes);
-    HDfprintf(stream, "%*s%-*s 0x%08x\n", indent, "", fwidth, "Filter mask:", key->filter_mask);
-    HDfprintf(stream, "%*s%-*s {", indent, "", fwidth, "Logical offset:");
-    for(u = 0; u < udata->mesg->u.chunk.ndims; u++)
-        HDfprintf(stream, "%s%Hd", u?", ":"", key->offset[u]);
-    HDfputs("}\n", stream);
+    /*
+     * The right key might already be present.  If not, then add a zero-width
+     * chunk.
+     */
+    if(H5B_INS_LEFT != op) {
+        rt_key->nbytes = 0;
+        rt_key->filter_mask = 0;
+        for(u = 0; u < udata->common.mesg->u.chunk.ndims; u++) {
+            HDassert(udata->common.offset[u] + udata->common.mesg->u.chunk.dim[u] >
+                udata->common.offset[u]);
+            rt_key->offset[u] = udata->common.offset[u] + udata->common.mesg->u.chunk.dim[u];
+        } /* end if */
+    } /* end if */
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
-} /* end H5D_istore_debug_key() */
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5D_btree_new_node() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_cmp2
+ * Function:	H5D_btree_cmp2
  *
  * Purpose:	Compares two keys sort of like strcmp().  The UDATA pointer
  *		is only to supply extra information not carried in the keys
@@ -401,15 +351,15 @@ H5D_istore_debug_key(FILE *stream, H5F_t UNUSED *f, hid_t UNUSED dxpl_id, int in
  */
 /* ARGSUSED */
 static int
-H5D_istore_cmp2(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_udata,
+H5D_btree_cmp2(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_udata,
 		void *_rt_key)
 {
-    H5D_istore_key_t	*lt_key = (H5D_istore_key_t *) _lt_key;
-    H5D_istore_key_t	*rt_key = (H5D_istore_key_t *) _rt_key;
-    H5D_istore_ud0_t	*udata = (H5D_istore_ud0_t *) _udata;
+    H5D_btree_key_t	*lt_key = (H5D_btree_key_t *) _lt_key;
+    H5D_btree_key_t	*rt_key = (H5D_btree_key_t *) _rt_key;
+    H5D_btree_ud0_t	*udata = (H5D_btree_ud0_t *) _udata;
     int		ret_value;
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_cmp2)
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_cmp2)
 
     HDassert(lt_key);
     HDassert(rt_key);
@@ -420,11 +370,11 @@ H5D_istore_cmp2(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_uda
     ret_value = H5V_vector_cmp_u(udata->mesg->u.chunk.ndims, lt_key->offset, rt_key->offset);
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_cmp2() */
+} /* end H5D_btree_cmp2() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_cmp3
+ * Function:	H5D_btree_cmp3
  *
  * Purpose:	Compare the requested datum UDATA with the left and right
  *		keys of the B-tree.
@@ -452,15 +402,15 @@ H5D_istore_cmp2(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_uda
  */
 /* ARGSUSED */
 static int
-H5D_istore_cmp3(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_udata,
+H5D_btree_cmp3(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_udata,
 		void *_rt_key)
 {
-    H5D_istore_key_t	*lt_key = (H5D_istore_key_t *) _lt_key;
-    H5D_istore_key_t	*rt_key = (H5D_istore_key_t *) _rt_key;
-    H5D_istore_ud0_t	*udata = (H5D_istore_ud0_t *) _udata;
+    H5D_btree_key_t	*lt_key = (H5D_btree_key_t *) _lt_key;
+    H5D_btree_key_t	*rt_key = (H5D_btree_key_t *) _rt_key;
+    H5D_btree_ud0_t	*udata = (H5D_btree_ud0_t *) _udata;
     int		ret_value = 0;
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_cmp3)
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_cmp3)
 
     HDassert(lt_key);
     HDassert(rt_key);
@@ -490,85 +440,11 @@ H5D_istore_cmp3(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, void *_lt_key, void *_uda
     } /* end else */
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_cmp3() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5D_istore_new_node
- *
- * Purpose:	Adds a new entry to an i-storage B-tree.  We can assume that
- *		the domain represented by UDATA doesn't intersect the domain
- *		already represented by the B-tree.
- *
- * Return:	Success:	Non-negative. The address of leaf is returned
- *				through the ADDR argument.  It is also added
- *				to the UDATA.
- *
- * 		Failure:	Negative
- *
- * Programmer:	Robb Matzke
- *		Tuesday, October 14, 1997
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5D_istore_new_node(H5F_t *f, hid_t dxpl_id, H5B_ins_t op,
-		    void *_lt_key, void *_udata, void *_rt_key,
-		    haddr_t *addr_p/*out*/)
-{
-    H5D_istore_key_t	*lt_key = (H5D_istore_key_t *) _lt_key;
-    H5D_istore_key_t	*rt_key = (H5D_istore_key_t *) _rt_key;
-    H5D_chunk_ud_t	*udata = (H5D_chunk_ud_t *) _udata;
-    unsigned		u;
-    herr_t      ret_value = SUCCEED;       /* Return value */
-
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_new_node)
-
-    /* check args */
-    HDassert(f);
-    HDassert(lt_key);
-    HDassert(rt_key);
-    HDassert(udata);
-    HDassert(udata->common.mesg->u.chunk.ndims > 0 && udata->common.mesg->u.chunk.ndims < H5O_LAYOUT_NDIMS);
-    HDassert(addr_p);
-
-    /* Allocate new storage */
-    HDassert(udata->nbytes > 0);
-    H5_CHECK_OVERFLOW(udata->nbytes, uint32_t, hsize_t);
-    if(HADDR_UNDEF == (*addr_p = H5MF_alloc(f, H5FD_MEM_DRAW, dxpl_id, (hsize_t)udata->nbytes)))
-        HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "couldn't allocate new file storage")
-    udata->addr = *addr_p;
-
-    /*
-     * The left key describes the storage of the UDATA chunk being
-     * inserted into the tree.
-     */
-    lt_key->nbytes = udata->nbytes;
-    lt_key->filter_mask = udata->filter_mask;
-    for(u = 0; u < udata->common.mesg->u.chunk.ndims; u++)
-        lt_key->offset[u] = udata->common.offset[u];
-
-    /*
-     * The right key might already be present.  If not, then add a zero-width
-     * chunk.
-     */
-    if(H5B_INS_LEFT != op) {
-        rt_key->nbytes = 0;
-        rt_key->filter_mask = 0;
-        for(u = 0; u < udata->common.mesg->u.chunk.ndims; u++) {
-            HDassert(udata->common.offset[u] + udata->common.mesg->u.chunk.dim[u] >
-                udata->common.offset[u]);
-            rt_key->offset[u] = udata->common.offset[u] + udata->common.mesg->u.chunk.dim[u];
-        } /* end if */
-    } /* end if */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_new_node() */
+} /* end H5D_btree_cmp3() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_found
+ * Function:	H5D_btree_found
  *
  * Purpose:	This function is called when the B-tree search engine has
  *		found the leaf entry that points to a chunk of storage that
@@ -593,15 +469,15 @@ done:
  */
 /* ARGSUSED */
 static htri_t
-H5D_istore_found(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, haddr_t addr, const void *_lt_key,
+H5D_btree_found(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, haddr_t addr, const void *_lt_key,
 		 void *_udata)
 {
     H5D_chunk_ud_t	   *udata = (H5D_chunk_ud_t *) _udata;
-    const H5D_istore_key_t *lt_key = (const H5D_istore_key_t *) _lt_key;
+    const H5D_btree_key_t *lt_key = (const H5D_btree_key_t *) _lt_key;
     unsigned		u;
     htri_t      ret_value = TRUE;       /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_istore_found)
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_found)
 
     /* Check arguments */
     HDassert(f);
@@ -622,11 +498,11 @@ H5D_istore_found(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, haddr_t addr, const void
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_found() */
+} /* end H5D_btree_found() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_insert
+ * Function:	H5D_btree_insert
  *
  * Purpose:	This function is called when the B-tree insert engine finds
  *		the node to use to insert new data.  The UDATA argument
@@ -655,21 +531,21 @@ done:
  */
 /* ARGSUSED */
 static H5B_ins_t
-H5D_istore_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
+H5D_btree_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
 		  hbool_t *lt_key_changed,
 		  void *_md_key, void *_udata, void *_rt_key,
 		  hbool_t UNUSED *rt_key_changed,
 		  haddr_t *new_node_p/*out*/)
 {
-    H5D_istore_key_t	*lt_key = (H5D_istore_key_t *) _lt_key;
-    H5D_istore_key_t	*md_key = (H5D_istore_key_t *) _md_key;
-    H5D_istore_key_t	*rt_key = (H5D_istore_key_t *) _rt_key;
+    H5D_btree_key_t	*lt_key = (H5D_btree_key_t *) _lt_key;
+    H5D_btree_key_t	*md_key = (H5D_btree_key_t *) _md_key;
+    H5D_btree_key_t	*rt_key = (H5D_btree_key_t *) _rt_key;
     H5D_chunk_ud_t	*udata = (H5D_chunk_ud_t *) _udata;
     int		cmp;
     unsigned		u;
     H5B_ins_t		ret_value;
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_insert)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_insert)
 
     /* check args */
     HDassert(f);
@@ -681,7 +557,7 @@ H5D_istore_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
     HDassert(rt_key);
     HDassert(new_node_p);
 
-    cmp = H5D_istore_cmp3(f, dxpl_id, lt_key, udata, rt_key);
+    cmp = H5D_btree_cmp3(f, dxpl_id, lt_key, udata, rt_key);
     HDassert(cmp <= 0);
 
     if(cmp < 0) {
@@ -759,11 +635,11 @@ H5D_istore_insert(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_insert() */
+} /* end H5D_btree_insert() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_remove
+ * Function:	H5D_btree_remove
  *
  * Purpose:	Removes chunks that are no longer necessary in the B-tree.
  *
@@ -777,16 +653,16 @@ done:
  */
 /* ARGSUSED */
 static H5B_ins_t
-H5D_istore_remove(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key /*in,out */ ,
+H5D_btree_remove(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key /*in,out */ ,
 	hbool_t *lt_key_changed /*out */ ,
 	void UNUSED * _udata /*in,out */ ,
 	void UNUSED * _rt_key /*in,out */ ,
 	hbool_t *rt_key_changed /*out */ )
 {
-    H5D_istore_key_t    *lt_key = (H5D_istore_key_t *)_lt_key;
+    H5D_btree_key_t    *lt_key = (H5D_btree_key_t *)_lt_key;
     H5B_ins_t ret_value=H5B_INS_REMOVE; /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_remove)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_remove)
 
     /* Remove raw data chunk from file */
     H5_CHECK_OVERFLOW(lt_key->nbytes, uint32_t, hsize_t);
@@ -799,11 +675,131 @@ H5D_istore_remove(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *_lt_key /*in,out
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_remove() */
+} /* end H5D_btree_remove() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D_btree_decode_key
+ *
+ * Purpose:	Decodes a raw key into a native key for the B-tree
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Friday, October 10, 1997
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_btree_decode_key(const H5F_t UNUSED *f, const H5B_t *bt, const uint8_t *raw, void *_key)
+{
+    H5D_btree_key_t	*key = (H5D_btree_key_t *) _key;
+    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
+    size_t		ndims;
+    unsigned		u;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_decode_key)
+
+    /* check args */
+    HDassert(f);
+    HDassert(bt);
+    shared = (H5B_shared_t *)H5RC_GET_OBJ(bt->rc_shared);
+    HDassert(shared);
+    HDassert(raw);
+    HDassert(key);
+    ndims = H5D_BTREE_NDIMS(shared);
+    HDassert(ndims <= H5O_LAYOUT_NDIMS);
+
+    /* decode */
+    UINT32DECODE(raw, key->nbytes);
+    UINT32DECODE(raw, key->filter_mask);
+    for(u = 0; u < ndims; u++)
+	UINT64DECODE(raw, key->offset[u]);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D_btree_decode_key() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D_btree_encode_key
+ *
+ * Purpose:	Encode a key from native format to raw format.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *		Friday, October 10, 1997
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_btree_encode_key(const H5F_t UNUSED *f, const H5B_t *bt, uint8_t *raw, void *_key)
+{
+    H5D_btree_key_t	*key = (H5D_btree_key_t *) _key;
+    H5B_shared_t        *shared;        /* Pointer to shared B-tree info */
+    size_t		ndims;
+    unsigned		u;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_encode_key)
+
+    /* check args */
+    HDassert(f);
+    HDassert(bt);
+    shared = (H5B_shared_t *)H5RC_GET_OBJ(bt->rc_shared);
+    HDassert(shared);
+    HDassert(raw);
+    HDassert(key);
+    ndims = H5D_BTREE_NDIMS(shared);
+    HDassert(ndims <= H5O_LAYOUT_NDIMS);
+
+    /* encode */
+    UINT32ENCODE(raw, key->nbytes);
+    UINT32ENCODE(raw, key->filter_mask);
+    for(u = 0; u < ndims; u++)
+	UINT64ENCODE(raw, key->offset[u]);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D_btree_encode_key() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5D_btree_debug_key
+ *
+ * Purpose:	Prints a key.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, April 16, 1998
+ *
+ *-------------------------------------------------------------------------
+ */
+/* ARGSUSED */
+static herr_t
+H5D_btree_debug_key(FILE *stream, H5F_t UNUSED *f, hid_t UNUSED dxpl_id, int indent, int fwidth,
+		      const void *_key, const void *_udata)
+{
+    const H5D_btree_key_t	*key = (const H5D_btree_key_t *)_key;
+    const H5D_btree_ud0_t	*udata = (const H5D_btree_ud0_t *)_udata;
+    unsigned		u;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5D_btree_debug_key)
+
+    HDassert(key);
+
+    HDfprintf(stream, "%*s%-*s %u bytes\n", indent, "", fwidth, "Chunk size:", (unsigned)key->nbytes);
+    HDfprintf(stream, "%*s%-*s 0x%08x\n", indent, "", fwidth, "Filter mask:", key->filter_mask);
+    HDfprintf(stream, "%*s%-*s {", indent, "", fwidth, "Logical offset:");
+    for(u = 0; u < udata->mesg->u.chunk.ndims; u++)
+        HDfprintf(stream, "%s%Hd", u?", ":"", key->offset[u]);
+    HDfputs("}\n", stream);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5D_btree_debug_key() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_shared_create
+ * Function:	H5D_btree_shared_create
  *
  * Purpose:	Create & initialize B-tree shared info
  *
@@ -815,13 +811,13 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_shared_create(const H5F_t *f, H5O_layout_t *layout)
+H5D_btree_shared_create(const H5F_t *f, H5O_layout_t *layout)
 {
     H5B_shared_t *shared;               /* Shared B-tree node info */
     size_t	sizeof_rkey;	        /* Size of raw (disk) key	     */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_shared_create)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_shared_create)
 
     /* Set the raw key size */
     sizeof_rkey = 4 +				/*storage size		*/
@@ -829,7 +825,7 @@ H5D_istore_shared_create(const H5F_t *f, H5O_layout_t *layout)
                 layout->u.chunk.ndims * 8;	/*dimension indices	*/
 
     /* Allocate & initialize global info for the shared structure */
-    if(NULL == (shared = H5B_shared_new(f, H5B_ISTORE, sizeof_rkey)))
+    if(NULL == (shared = H5B_shared_new(f, H5B_BTREE, sizeof_rkey)))
 	HGOTO_ERROR(H5E_BTREE, H5E_NOSPACE, FAIL, "memory allocation failed for shared B-tree info")
 
     /* Set up the "local" information for this dataset's chunks */
@@ -841,11 +837,11 @@ H5D_istore_shared_create(const H5F_t *f, H5O_layout_t *layout)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_shared_create() */
+} /* end H5D_btree_shared_create() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_init
+ * Function:	H5D_btree_idx_init
  *
  * Purpose:	Initialize the indexing information for a dataset.
  *
@@ -857,11 +853,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_init(const H5D_chk_idx_info_t *idx_info)
+H5D_btree_idx_init(const H5D_chk_idx_info_t *idx_info)
 {
     herr_t      ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_init)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_init)
 
     /* Check args */
     HDassert(idx_info);
@@ -869,16 +865,16 @@ H5D_istore_idx_init(const H5D_chk_idx_info_t *idx_info)
     HDassert(idx_info->layout);
 
     /* Allocate the shared structure */
-    if(H5D_istore_shared_create(idx_info->f, idx_info->layout) < 0)
+    if(H5D_btree_shared_create(idx_info->f, idx_info->layout) < 0)
 	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create wrapper for shared B-tree info")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_init() */
+} /* end H5D_btree_idx_init() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_create
+ * Function:	H5D_btree_idx_create
  *
  * Purpose:	Creates a new indexed-storage B-tree and initializes the
  *		layout struct with information about the storage.  The
@@ -896,12 +892,12 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_create(const H5D_chk_idx_info_t *idx_info)
+H5D_btree_idx_create(const H5D_chk_idx_info_t *idx_info)
 {
-    H5D_istore_ud0_t udata;             /* User data for B-tree callback */
+    H5D_btree_ud0_t udata;             /* User data for B-tree callback */
     herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_create)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_create)
 
     /* Check args */
     HDassert(idx_info);
@@ -912,16 +908,16 @@ H5D_istore_idx_create(const H5D_chk_idx_info_t *idx_info)
     udata.mesg = idx_info->layout;
 
     /* Create the v1 B-tree for the chunk index */
-    if(H5B_create(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, &udata, &(idx_info->layout->u.chunk.addr)/*out*/) < 0)
+    if(H5B_create(idx_info->f, idx_info->dxpl_id, H5B_BTREE, &udata, &(idx_info->layout->u.chunk.addr)/*out*/) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't create B-tree")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_create() */
+} /* end H5D_btree_idx_create() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_insert
+ * Function:	H5D_btree_idx_insert
  *
  * Purpose:	Create the chunk it if it doesn't exist, or reallocate the
  *              chunk if its size changed.
@@ -934,11 +930,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
+H5D_btree_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 {
     herr_t	ret_value = SUCCEED;		/* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_insert)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_insert)
 
     HDassert(idx_info);
     HDassert(idx_info->f);
@@ -949,16 +945,16 @@ H5D_istore_idx_insert(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
      * Create the chunk it if it doesn't exist, or reallocate the chunk if
      * its size changed.
      */
-    if(H5B_insert(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, idx_info->layout->u.chunk.addr, udata) < 0)
+    if(H5B_insert(idx_info->f, idx_info->dxpl_id, H5B_BTREE, idx_info->layout->u.chunk.addr, udata) < 0)
         HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to allocate chunk")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5D_istore_idx_insert() */
+} /* H5D_btree_idx_insert() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_get_addr
+ * Function:	H5D_btree_idx_get_addr
  *
  * Purpose:	Get the file address of a chunk if file space has been
  *		assigned.  Save the retrieved information in the udata
@@ -972,11 +968,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
+H5D_btree_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udata)
 {
     herr_t	ret_value = SUCCEED;	/* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_get_addr)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_get_addr)
 
     HDassert(idx_info);
     HDassert(idx_info->f);
@@ -985,16 +981,16 @@ H5D_istore_idx_get_addr(const H5D_chk_idx_info_t *idx_info, H5D_chunk_ud_t *udat
     HDassert(udata);
 
     /* Go get the chunk information from the B-tree */
-    if(H5B_find(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, idx_info->layout->u.chunk.addr, udata) < 0)
+    if(H5B_find(idx_info->f, idx_info->dxpl_id, H5B_BTREE, idx_info->layout->u.chunk.addr, udata) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get chunk info")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5D_istore_idx_get_addr() */
+} /* H5D_btree_idx_get_addr() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_iterate_cb
+ * Function:	H5D_btree_idx_iterate_cb
  *
  * Purpose:	Translate the B-tree specific chunk record into a generic
  *              form and make the callback to the generic chunk callback
@@ -1010,23 +1006,23 @@ done:
  */
 /* ARGSUSED */
 static int
-H5D_istore_idx_iterate_cb(H5F_t UNUSED *f, hid_t UNUSED dxpl_id,
+H5D_btree_idx_iterate_cb(H5F_t UNUSED *f, hid_t UNUSED dxpl_id,
     const void *_lt_key, haddr_t addr, const void UNUSED *_rt_key,
     void *_udata)
 {
-    H5D_istore_it_ud_t	*udata = (H5D_istore_it_ud_t *)_udata; /* User data */
-    const H5D_istore_key_t	*lt_key = (const H5D_istore_key_t *)_lt_key; /* B-tree key for chunk */
+    H5D_btree_it_ud_t	*udata = (H5D_btree_it_ud_t *)_udata; /* User data */
+    const H5D_btree_key_t	*lt_key = (const H5D_btree_key_t *)_lt_key; /* B-tree key for chunk */
     H5D_chunk_rec_t chunk_rec;  /* Generic chunk record for callback */
     int ret_value;              /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_iterate_cb)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_iterate_cb)
 
     /* Sanity check for memcpy() */
-    HDcompile_assert(offsetof(H5D_chunk_rec_t, nbytes) == offsetof(H5D_istore_key_t, nbytes));
+    HDcompile_assert(offsetof(H5D_chunk_rec_t, nbytes) == offsetof(H5D_btree_key_t, nbytes));
     HDcompile_assert(sizeof(chunk_rec.nbytes) == sizeof(lt_key->nbytes));
-    HDcompile_assert(offsetof(H5D_chunk_rec_t, offset) == offsetof(H5D_istore_key_t, offset));
+    HDcompile_assert(offsetof(H5D_chunk_rec_t, offset) == offsetof(H5D_btree_key_t, offset));
     HDcompile_assert(sizeof(chunk_rec.offset) == sizeof(lt_key->offset));
-    HDcompile_assert(offsetof(H5D_chunk_rec_t, filter_mask) == offsetof(H5D_istore_key_t, filter_mask));
+    HDcompile_assert(offsetof(H5D_chunk_rec_t, filter_mask) == offsetof(H5D_btree_key_t, filter_mask));
     HDcompile_assert(sizeof(chunk_rec.filter_mask) == sizeof(lt_key->filter_mask));
 
     /* Compose generic chunk record for callback */
@@ -1038,11 +1034,11 @@ H5D_istore_idx_iterate_cb(H5F_t UNUSED *f, hid_t UNUSED dxpl_id,
         HERROR(H5E_DATASET, H5E_CALLBACK, "failure in generic chunk iterator callback");
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5D_istore_idx_iterate_cb() */
+} /* H5D_btree_idx_iterate_cb() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_iterate
+ * Function:	H5D_btree_idx_iterate
  *
  * Purpose:	Iterate over the chunks in the B-tree index, making a callback
  *              for each one.
@@ -1055,13 +1051,13 @@ H5D_istore_idx_iterate_cb(H5F_t UNUSED *f, hid_t UNUSED dxpl_id,
  *-------------------------------------------------------------------------
  */
 static int
-H5D_istore_idx_iterate(const H5D_chk_idx_info_t *idx_info,
+H5D_btree_idx_iterate(const H5D_chk_idx_info_t *idx_info,
     H5D_chunk_cb_func_t chunk_cb, void *chunk_udata)
 {
-    H5D_istore_it_ud_t	udata;  /* User data for B-tree iterator callback */
+    H5D_btree_it_ud_t	udata;  /* User data for B-tree iterator callback */
     int ret_value;              /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_iterate)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_iterate)
 
     HDassert(idx_info);
     HDassert(idx_info->f);
@@ -1076,15 +1072,15 @@ H5D_istore_idx_iterate(const H5D_chk_idx_info_t *idx_info,
     udata.udata = chunk_udata;
 
     /* Iterate over existing chunks */
-    if((ret_value = H5B_iterate(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, idx_info->layout->u.chunk.addr, H5D_istore_idx_iterate_cb, &udata)) < 0)
+    if((ret_value = H5B_iterate(idx_info->f, idx_info->dxpl_id, H5B_BTREE, idx_info->layout->u.chunk.addr, H5D_btree_idx_iterate_cb, &udata)) < 0)
         HERROR(H5E_DATASET, H5E_BADITER, "unable to iterate over chunk B-tree");
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_iterate() */
+} /* end H5D_btree_idx_iterate() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_remove
+ * Function:	H5D_btree_idx_remove
  *
  * Purpose:	Remove chunk from v1 B-tree index.
  *
@@ -1096,11 +1092,11 @@ H5D_istore_idx_iterate(const H5D_chk_idx_info_t *idx_info,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t *udata)
+H5D_btree_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t *udata)
 {
     herr_t	ret_value = SUCCEED;		/* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_remove)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_remove)
 
     HDassert(idx_info);
     HDassert(idx_info->f);
@@ -1110,16 +1106,16 @@ H5D_istore_idx_remove(const H5D_chk_idx_info_t *idx_info, H5D_chunk_common_ud_t
     /* Remove the chunk from the v1 B-tree index and release the space for the
      * chunk (in the B-tree callback).
      */
-    if(H5B_remove(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, idx_info->layout->u.chunk.addr, udata) < 0)
+    if(H5B_remove(idx_info->f, idx_info->dxpl_id, H5B_BTREE, idx_info->layout->u.chunk.addr, udata) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTDELETE, FAIL, "unable to remove chunk entry")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5D_istore_idx_remove() */
+} /* H5D_btree_idx_remove() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_delete
+ * Function:	H5D_btree_idx_delete
  *
  * Purpose:	Delete v1 B-tree index and raw data storage for entire dataset
  *              (i.e. all chunks)
@@ -1133,13 +1129,13 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_delete(const H5D_chk_idx_info_t *idx_info)
+H5D_btree_idx_delete(const H5D_chk_idx_info_t *idx_info)
 {
     H5O_layout_t tmp_layout;        /* Local copy of layout info */
-    H5D_istore_ud0_t	udata;      /* User data for B-tree iterator call */
+    H5D_btree_ud0_t	udata;      /* User data for B-tree iterator call */
     herr_t ret_value = SUCCEED;     /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_delete)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_delete)
 
     /* Sanity checks */
     HDassert(idx_info);
@@ -1153,11 +1149,11 @@ H5D_istore_idx_delete(const H5D_chk_idx_info_t *idx_info)
     udata.mesg = &tmp_layout;
 
     /* Set up the shared structure */
-    if(H5D_istore_shared_create(idx_info->f, &tmp_layout) < 0)
+    if(H5D_btree_shared_create(idx_info->f, &tmp_layout) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "can't create wrapper for shared B-tree info")
 
     /* Delete entire B-tree */
-    if(H5B_delete(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, tmp_layout.u.chunk.addr, &udata) < 0)
+    if(H5B_delete(idx_info->f, idx_info->dxpl_id, H5B_BTREE, tmp_layout.u.chunk.addr, &udata) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTDELETE, FAIL, "unable to delete chunk B-tree")
 
     /* Free the raw B-tree node buffer */
@@ -1168,11 +1164,11 @@ H5D_istore_idx_delete(const H5D_chk_idx_info_t *idx_info)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_delete() */
+} /* end H5D_btree_idx_delete() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_copy_setup
+ * Function:	H5D_btree_idx_copy_setup
  *
  * Purpose:	Set up any necessary information for copying chunks
  *
@@ -1184,12 +1180,12 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
+H5D_btree_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
     const H5D_chk_idx_info_t *idx_info_dst)
 {
     herr_t      ret_value = SUCCEED;        /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_copy_setup)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_copy_setup)
 
     HDassert(idx_info_src);
     HDassert(idx_info_src->f);
@@ -1200,22 +1196,22 @@ H5D_istore_idx_copy_setup(const H5D_chk_idx_info_t *idx_info_src,
     HDassert(!H5F_addr_defined(idx_info_dst->layout->u.chunk.addr));
 
     /* Create shared B-tree info for each file */
-    if(H5D_istore_shared_create(idx_info_src->f, idx_info_src->layout) < 0)
+    if(H5D_btree_shared_create(idx_info_src->f, idx_info_src->layout) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create wrapper for source shared B-tree info")
-    if(H5D_istore_shared_create(idx_info_dst->f, idx_info_dst->layout) < 0)
+    if(H5D_btree_shared_create(idx_info_dst->f, idx_info_dst->layout) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create wrapper for destination shared B-tree info")
 
     /* Create the root of the B-tree that describes chunked storage in the dest. file */
-    if(H5D_istore_idx_create(idx_info_dst) < 0)
+    if(H5D_btree_idx_create(idx_info_dst) < 0)
         HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to initialize chunked storage")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_copy_setup() */
+} /* end H5D_btree_idx_copy_setup() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_copy_shutdown
+ * Function:	H5D_btree_idx_copy_shutdown
  *
  * Purpose:	Shutdown any information from copying chunks
  *
@@ -1227,11 +1223,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_copy_shutdown(H5O_layout_t *layout_src, H5O_layout_t *layout_dst)
+H5D_btree_idx_copy_shutdown(H5O_layout_t *layout_src, H5O_layout_t *layout_dst)
 {
     herr_t      ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_copy_shutdown)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_copy_shutdown)
 
     HDassert(layout_src);
     HDassert(layout_dst);
@@ -1244,11 +1240,11 @@ H5D_istore_idx_copy_shutdown(H5O_layout_t *layout_src, H5O_layout_t *layout_dst)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_copy_shutdown() */
+} /* end H5D_btree_idx_copy_shutdown() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5D_istore_idx_size
+ * Function:    H5D_btree_idx_size
  *
  * Purpose:     Retrieve the amount of B-tree storage for chunked dataset
  *
@@ -1261,14 +1257,14 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D_istore_idx_size(const H5D_chk_idx_info_t *idx_info, hsize_t *index_size)
+H5D_btree_idx_size(const H5D_chk_idx_info_t *idx_info, hsize_t *index_size)
 {
-    H5D_istore_ud0_t udata;             /* User-data for loading istore nodes */
+    H5D_btree_ud0_t udata;             /* User-data for loading btree nodes */
     H5B_info_t bt_info;                 /* B-tree info */
     hbool_t shared_init = FALSE;        /* Whether shared B-tree info is initialized */
     herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI(H5D_istore_idx_size, FAIL)
+    FUNC_ENTER_NOAPI(H5D_btree_idx_size, FAIL)
 
     /* Check args */
     HDassert(idx_info);
@@ -1277,16 +1273,16 @@ H5D_istore_idx_size(const H5D_chk_idx_info_t *idx_info, hsize_t *index_size)
     HDassert(index_size);
 
     /* Initialize the shared info for the B-tree traversal */
-    if(H5D_istore_shared_create(idx_info->f, idx_info->layout) < 0)
+    if(H5D_btree_shared_create(idx_info->f, idx_info->layout) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create wrapper for shared B-tree info")
     shared_init = TRUE;
 
-    /* Initialize istore node user-data */
+    /* Initialize btree node user-data */
     HDmemset(&udata, 0, sizeof udata);
     udata.mesg = idx_info->layout;
 
     /* Get metadata information for B-tree */
-    if(H5B_get_info(idx_info->f, idx_info->dxpl_id, H5B_ISTORE, idx_info->layout->u.chunk.addr, &bt_info, NULL, &udata) < 0)
+    if(H5B_get_info(idx_info->f, idx_info->dxpl_id, H5B_BTREE, idx_info->layout->u.chunk.addr, &bt_info, NULL, &udata) < 0)
         HGOTO_ERROR(H5E_BTREE, H5E_CANTINIT, FAIL, "unable to iterate over chunk B-tree")
 
     /* Set the size of the B-tree */
@@ -1301,11 +1297,11 @@ done:
     } /* end if */
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_size() */
+} /* end H5D_btree_idx_size() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_idx_dest
+ * Function:	H5D_btree_idx_dest
  *
  * Purpose:	Release indexing information in memory.
  *
@@ -1317,11 +1313,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_istore_idx_dest(const H5D_chk_idx_info_t *idx_info)
+H5D_btree_idx_dest(const H5D_chk_idx_info_t *idx_info)
 {
     herr_t      ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT(H5D_istore_idx_dest)
+    FUNC_ENTER_NOAPI_NOINIT(H5D_btree_idx_dest)
 
     HDassert(idx_info);
     HDassert(idx_info->f);
@@ -1335,11 +1331,11 @@ H5D_istore_idx_dest(const H5D_chk_idx_info_t *idx_info)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_idx_dest() */
+} /* end H5D_btree_idx_dest() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_debug
+ * Function:	H5D_btree_debug
  *
  * Purpose:	Debugs a B-tree node for indexed raw data storage.
  *
@@ -1351,21 +1347,21 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5D_istore_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE * stream, int indent,
+H5D_btree_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE * stream, int indent,
 		 int fwidth, unsigned ndims)
 {
-    H5D_istore_ud0_t	udata;          /* B-tree user data */
+    H5D_btree_ud0_t	udata;          /* B-tree user data */
     H5O_layout_t        layout;         /* Layout information for B-tree callback */
     hbool_t     shared_init = FALSE;    /* Whether B-tree shared info is initialized */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_NOAPI(H5D_istore_debug, FAIL)
+    FUNC_ENTER_NOAPI(H5D_btree_debug, FAIL)
 
     /* Set up "fake" layout info */
     layout.u.chunk.ndims = ndims;
 
     /* Allocate the shared structure */
-    if(H5D_istore_shared_create(f, &layout) < 0)
+    if(H5D_btree_shared_create(f, &layout) < 0)
 	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't create wrapper for shared B-tree info")
     shared_init = TRUE;
 
@@ -1373,7 +1369,7 @@ H5D_istore_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE * stream, int inden
     HDmemset(&udata, 0, sizeof udata);
     udata.mesg = &layout;
 
-    (void)H5B_debug(f, dxpl_id, addr, stream, indent, fwidth, H5B_ISTORE, &udata);
+    (void)H5B_debug(f, dxpl_id, addr, stream, indent, fwidth, H5B_BTREE, &udata);
 
 done:
     if(shared_init) {
@@ -1385,5 +1381,5 @@ done:
     } /* end if */
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5D_istore_debug() */
+} /* end H5D_btree_debug() */
 
diff --git a/src/H5Dchunk.c b/src/H5Dchunk.c
index 6058e16..82168a1 100644
--- a/src/H5Dchunk.c
+++ b/src/H5Dchunk.c
@@ -2982,7 +2982,7 @@ H5D_chunk_allocate(H5D_t *dset, hid_t dxpl_id, hbool_t full_overwrite)
 
         /* Get the chunk's info */
         if(H5D_chunk_get_info(dset, dxpl_id, chunk_offset, &udata) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, NULL, "error looking up chunk address")
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "error looking up chunk address")
 
         /* Check if the chunk exists yet on disk */
         if(!H5F_addr_defined(udata.addr)) {
@@ -4219,7 +4219,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5D_istore_iter_dump
+ * Function:	H5D_chunk_iter_dump
  *
  * Purpose:	If the UDATA.STREAM member is non-null then debugging
  *              information is written to that stream.
diff --git a/src/H5Dint.c b/src/H5Dint.c
index 02be08c..3018108 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -720,8 +720,8 @@ H5D_set_io_ops(H5D_t *dataset)
             dataset->shared->layout.ops = H5D_LOPS_CHUNK;
 
             /* Set the chunk operations */
-            /* (Only "istore" indexing type currently supported */
-            dataset->shared->layout.u.chunk.ops = H5D_COPS_ISTORE;
+            /* (Only "B-tree" indexing type currently supported */
+            dataset->shared->layout.u.chunk.ops = H5D_COPS_BTREE;
             break;
 
         case H5D_COMPACT:
diff --git a/src/H5Dpkg.h b/src/H5Dpkg.h
index bbd3a42..b0d7d6a 100644
--- a/src/H5Dpkg.h
+++ b/src/H5Dpkg.h
@@ -496,7 +496,7 @@ H5_DLLVAR const H5D_layout_ops_t H5D_LOPS_COMPACT[1];
 H5_DLLVAR const H5D_layout_ops_t H5D_LOPS_CHUNK[1];
 
 /* Chunked layout operations */
-H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_ISTORE[1];
+H5_DLLVAR const H5D_chunk_ops_t H5D_COPS_BTREE[1];
 
 
 /******************************/
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index 63aadbb..96a35cc 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -167,7 +167,7 @@ H5_DLL herr_t H5D_contig_delete(H5F_t *f, hid_t dxpl_id,
 H5_DLL herr_t H5D_chunk_delete(H5F_t *f, hid_t dxpl_id, H5O_layout_t *layout);
 
 /* Functions that operate on indexed storage */
-H5_DLL herr_t H5D_istore_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE * stream,
+H5_DLL herr_t H5D_btree_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE * stream,
 				int indent, int fwidth, unsigned ndims);
 
 #endif /* _H5Dprivate_H */
diff --git a/src/H5F.c b/src/H5F.c
index 7731966..3789fec 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -967,7 +967,7 @@ H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id, H5FD_t *lf)
          * and set the version # of the superblock to 1 if it is a non-default
          * value.
          */
-        else if(f->shared->btree_k[H5B_ISTORE_ID] != HDF5_BTREE_ISTORE_IK_DEF)
+        else if(f->shared->btree_k[H5B_CHUNK_ID] != HDF5_BTREE_CHUNK_IK_DEF)
             super_vers = HDF5_SUPERBLOCK_VERSION_1;
 
         /* If a newer superblock version is required, set it here */
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 338e83f..fb28c4e 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -397,7 +397,7 @@ typedef struct H5F_blk_aggr_t H5F_blk_aggr_t;
 
 /* B-tree internal 'K' values */
 #define HDF5_BTREE_SNODE_IK_DEF         16
-#define HDF5_BTREE_ISTORE_IK_DEF        32      /* Note! this value is assumed
+#define HDF5_BTREE_CHUNK_IK_DEF         32      /* Note! this value is assumed
                                                     to be 32 for version 0
                                                     of the superblock and
                                                     if it is changed, the code
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index bd2fe20..3c914bd 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -365,13 +365,13 @@ H5F_super_read(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc)
          * storage B-tree internal 'K' value
          */
         if(super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
-            UINT16DECODE(p, btree_k[H5B_ISTORE_ID]);
+            UINT16DECODE(p, btree_k[H5B_CHUNK_ID]);
             /* Reserved bytes are present only in version 1 */
             if(super_vers == HDF5_SUPERBLOCK_VERSION_1)
                 p += 2;   /* reserved */
         } /* end if */
         else
-            btree_k[H5B_ISTORE_ID] = HDF5_BTREE_ISTORE_IK_DEF;
+            btree_k[H5B_CHUNK_ID] = HDF5_BTREE_CHUNK_IK_DEF;
 
         /* Set the B-tree internal node values, etc */
         if(H5P_set(c_plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
@@ -632,7 +632,7 @@ H5F_super_read(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "v1 B-tree 'K' info message not present")
 
             /* Set non-default v1 B-tree 'K' value info from file */
-            shared->btree_k[H5B_ISTORE_ID] = btreek.btree_k[H5B_ISTORE_ID];
+            shared->btree_k[H5B_CHUNK_ID] = btreek.btree_k[H5B_CHUNK_ID];
             shared->btree_k[H5B_SNODE_ID] = btreek.btree_k[H5B_SNODE_ID];
             shared->sym_leaf_k = btreek.sym_leaf_k;
 
@@ -644,7 +644,7 @@ H5F_super_read(H5F_t *f, hid_t dxpl_id, H5G_loc_t *root_loc)
         } /* end if */
         else {
             /* No non-default v1 B-tree 'K' value info in file, use defaults */
-            shared->btree_k[H5B_ISTORE_ID] = HDF5_BTREE_ISTORE_IK_DEF;
+            shared->btree_k[H5B_CHUNK_ID] = HDF5_BTREE_CHUNK_IK_DEF;
             shared->btree_k[H5B_SNODE_ID] = HDF5_BTREE_SNODE_IK_DEF;
             shared->sym_leaf_k = H5F_CRT_SYM_LEAF_DEF;
         } /* end if */
@@ -767,7 +767,7 @@ H5F_super_init(H5F_t *f, hid_t dxpl_id)
     else if(super_vers >= HDF5_SUPERBLOCK_VERSION_2) {
         /* Check for non-default v1 B-tree 'K' values to store */
         if(f->shared->btree_k[H5B_SNODE_ID] != HDF5_BTREE_SNODE_IK_DEF ||
-                f->shared->btree_k[H5B_ISTORE_ID] != HDF5_BTREE_ISTORE_IK_DEF ||
+                f->shared->btree_k[H5B_CHUNK_ID] != HDF5_BTREE_CHUNK_IK_DEF ||
                 f->shared->sym_leaf_k != H5F_CRT_SYM_LEAF_DEF)
             need_ext = TRUE;
         /* Check for driver info to store */
@@ -809,12 +809,12 @@ H5F_super_init(H5F_t *f, hid_t dxpl_id)
 
         /* Check for non-default v1 B-tree 'K' values to store */
         if(f->shared->btree_k[H5B_SNODE_ID] != HDF5_BTREE_SNODE_IK_DEF ||
-                f->shared->btree_k[H5B_ISTORE_ID] != HDF5_BTREE_ISTORE_IK_DEF ||
+                f->shared->btree_k[H5B_CHUNK_ID] != HDF5_BTREE_CHUNK_IK_DEF ||
                 f->shared->sym_leaf_k != H5F_CRT_SYM_LEAF_DEF) {
             H5O_btreek_t btreek;        /* v1 B-tree 'K' value message for superblock extension */
 
             /* Write v1 B-tree 'K' value information to the superblock extension */
-            btreek.btree_k[H5B_ISTORE_ID] = f->shared->btree_k[H5B_ISTORE_ID];
+            btreek.btree_k[H5B_CHUNK_ID] = f->shared->btree_k[H5B_CHUNK_ID];
             btreek.btree_k[H5B_SNODE_ID] = f->shared->btree_k[H5B_SNODE_ID];
             btreek.sym_leaf_k = f->shared->sym_leaf_k;
             if(H5O_msg_create(&ext_loc, H5O_BTREEK_ID, H5O_MSG_FLAG_CONSTANT | H5O_MSG_FLAG_DONTSHARE, H5O_UPDATE_TIME, &btreek, dxpl_id) < 0)
@@ -918,7 +918,7 @@ H5F_super_write(H5F_t *f, hid_t dxpl_id)
          * internal 'K' value stored
          */
         if(super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
-            UINT16ENCODE(p, f->shared->btree_k[H5B_ISTORE_ID]);
+            UINT16ENCODE(p, f->shared->btree_k[H5B_CHUNK_ID]);
             *p++ = 0;   /*reserved */
             *p++ = 0;   /*reserved */
         } /* end if */
diff --git a/src/H5Obtreek.c b/src/H5Obtreek.c
index 2311212..36e4c1a 100644
--- a/src/H5Obtreek.c
+++ b/src/H5Obtreek.c
@@ -100,7 +100,7 @@ H5O_btreek_decode(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_fl
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for v1 B-tree 'K' message")
 
     /* Retrieve non-default B-tree 'K' values */
-    UINT16DECODE(p, mesg->btree_k[H5B_ISTORE_ID]);
+    UINT16DECODE(p, mesg->btree_k[H5B_CHUNK_ID]);
     UINT16DECODE(p, mesg->btree_k[H5B_SNODE_ID]);
     UINT16DECODE(p, mesg->sym_leaf_k);
 
@@ -138,7 +138,7 @@ H5O_btreek_encode(H5F_t UNUSED *f, hbool_t UNUSED disable_shared, uint8_t *p, co
 
     /* Store version and non-default v1 B-tree 'K' values */
     *p++ = H5O_BTREEK_VERSION;
-    UINT16ENCODE(p, mesg->btree_k[H5B_ISTORE_ID]);
+    UINT16ENCODE(p, mesg->btree_k[H5B_CHUNK_ID]);
     UINT16ENCODE(p, mesg->btree_k[H5B_SNODE_ID]);
     UINT16ENCODE(p, mesg->sym_leaf_k);
 
@@ -211,7 +211,7 @@ H5O_btreek_size(const H5F_t UNUSED *f, hbool_t UNUSED disable_shared, const void
     HDassert(f);
 
     ret_value = 1 +             /* Version number */
-		2 +             /* Indexed storage internal B-tree 'K' value */
+		2 +             /* Chunked storage internal B-tree 'K' value */
 		2 +             /* Symbol table node internal B-tree 'K' value */
 		2;              /* Symbol table node leaf 'K' value */
 
@@ -247,7 +247,7 @@ H5O_btreek_debug(H5F_t UNUSED *f, hid_t UNUSED dxpl_id, const void *_mesg, FILE
     HDassert(fwidth >= 0);
 
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-	      "Indexed storage internal B-tree 'K' value:", mesg->btree_k[H5B_ISTORE_ID]);
+	      "Chunked storage internal B-tree 'K' value:", mesg->btree_k[H5B_CHUNK_ID]);
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "Symbol table node internal B-tree 'K' value:", mesg->btree_k[H5B_SNODE_ID]);
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index f6d9534..c54fbe1 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -151,7 +151,7 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_flags,
 
             /* Set the chunk operations */
             /* (Only "istore" indexing type currently supported */
-            mesg->u.chunk.ops = H5D_COPS_ISTORE;
+            mesg->u.chunk.ops = H5D_COPS_BTREE;
         } /* end if */
         else {
             /* Sanity check */
@@ -240,7 +240,7 @@ H5O_layout_decode(H5F_t *f, hid_t UNUSED dxpl_id, unsigned UNUSED mesg_flags,
 
                 /* Set the chunk operations */
                 /* (Only "istore" indexing type currently supported */
-                mesg->u.chunk.ops = H5D_COPS_ISTORE;
+                mesg->u.chunk.ops = H5D_COPS_BTREE;
                 break;
 
             default:
diff --git a/src/H5Pfcpl.c b/src/H5Pfcpl.c
index e7f0518..a7956e7 100644
--- a/src/H5Pfcpl.c
+++ b/src/H5Pfcpl.c
@@ -53,7 +53,7 @@
 #define H5F_CRT_SYM_LEAF_SIZE        sizeof(unsigned)
 /* Definitions for the 1/2 rank for btree internal nodes    */
 #define H5F_CRT_BTREE_RANK_SIZE      sizeof(unsigned[H5B_NUM_BTREE_ID])
-#define H5F_CRT_BTREE_RANK_DEF       {HDF5_BTREE_SNODE_IK_DEF,HDF5_BTREE_ISTORE_IK_DEF}
+#define H5F_CRT_BTREE_RANK_DEF       {HDF5_BTREE_SNODE_IK_DEF,HDF5_BTREE_CHUNK_IK_DEF}
 /* Definitions for byte number in an address                */
 #define H5F_CRT_ADDR_BYTE_NUM_SIZE   sizeof(size_t)
 #define H5F_CRT_ADDR_BYTE_NUM_DEF    H5F_OBJ_ADDR_SIZE
@@ -593,7 +593,7 @@ H5Pset_istore_k(hid_t plist_id, unsigned ik)
     /* Set value */
     if(H5P_get(plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get rank for btree interanl nodes");
-    btree_k[H5B_ISTORE_ID] = ik;
+    btree_k[H5B_CHUNK_ID] = ik;
     if(H5P_set(plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set rank for btree interanl nodes");
 
@@ -641,7 +641,7 @@ H5Pget_istore_k(hid_t plist_id, unsigned *ik /*out */ )
     if(ik) {
         if(H5P_get(plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get rank for btree interanl nodes");
-        *ik = btree_k[H5B_ISTORE_ID];
+        *ik = btree_k[H5B_CHUNK_ID];
     } /* end if */
 
 done: